Shamans are unique in that they have an extreme amount of utility which lends itself nicely to the synergy/resources that Multiboxers have readily available. Totems make dealing with things that are usually a major obstacle to Multiboxers, i.e fear, crowd control.... totally trivial.

Multiboxing isnt really a "beginner" WoW subject, I'd suggest playing to 70 the normal way before you start Multiboxing.